1. Field of the Invention
The present invention relates to a plasma display panel and a method of manufacturing partitions thereof, and more particularly, to a plasma display panel in which neon light emission due to mis-discharge in a non-light emitting zone is fundamentally removed, and to a method of manufacturing partitions thereof.
2. Description of the Related Art
A typical plasma display device for displaying an image by using a gas discharge phenomenon is widely noted for its superior display capabilities (display capacity, brightness, contrast, afterimage, and a viewing angle) so as to replace a cathode ray tube (“CRT”). In the plasma display device, discharge is generated between electrodes in a gas by direct current or alternating current applied to the electrodes. Then, a fluorescent substance is excited by an ultraviolet ray radiated as the discharge is generated, and a light is emitted.
FIG. 1 is an exploded perspective view showing a panel of a typical alternating current type plasma display device. Referring to the drawing, a first electrode 13a, which is a transparent display electrode, and a second electrode 13b, which is an address electrode, are formed between a front glass substrate 11 and a rear glass substrate 12. The first electrode 13a includes an X electrode and a Y electrode. A sustaining discharge is generated between a pair of the first electrodes 13a during operation of the panel. The first and second electrodes 13a and 13b are formed in strips, facing to each other, on the inner surfaces of the front glass substrate 11 and the rear glass substrate 12, respectively. When the front and rear glass substrates 11 and 12 are coupled to each other, the first and second electrodes 13a and 13b cross each other. A dielectric layer 14 and a protective layer 15 are stacked in order on the inner surface of the front glass substrate 11. Partitions 17 are formed on the upper surface of a dielectric layer 14′ formed on the rear glass substrate 12. A cell 19 is formed by the partitions 17 and is filled with an inert gas such as neon (Ne) and xenon (Xe). A fluorescent substance 18 is coated on a predetermined portion of the inside of each cell 19. A bus electrode 13c is formed on the surface of the first electrode 13a to prevent line resistance, which increases as the length of the first electrode 13a increases.
In the operation of the plasma display device having the above structure, first, a high voltage (a trigger voltage) is applied to generate a discharge between the X electrode of the first electrode 13a and the second electrode 13b. When anions are accumulated in the dielectric layer 14 by the trigger voltage, the discharge is generated. When the trigger voltage exceeds a threshold voltage, the discharge gas in the cell 19 becomes a plasma state by the discharge. Thus, a stable discharge state can be maintained between pairs of the first electrodes 13a (see FIG. 2). In this sustaining discharge state, of the discharge lights generated, light in a range of an ultraviolet area collides with the fluorescent substance 18 and emits another light. Accordingly, each pixel formed by a unit of the cell 19 can display an image.
FIG. 2 is a sectional view showing the assembled plasma display panel of FIG. 1 by cutting the partitions in a widthwise direction. The same reference numerals are used for the same elements shown in FIGS. 1 and 2.
Referring to the drawing, the front glass substrate 11 and the rear glass substrate 12 are coupled to each other with the partitions 17 interposed therebetween. Such coupling is made by a sealing material having similar properties to those of a substrate material such as a frit glass 22 coated between the front and rear glass substrates 11 and 12. The frit glass 22 is coated on the inner surfaces of the front and rear substrates 11 and 12 along the edge thereof. The frit glass 22 is heated and melted in a state in which the front and rear substrates 11 and 12 are pressed against each other, and then is solidified so that the substrates 11 and 12 can be combined by being attached to each other.
An outermost partition 23 is positioned at the edge of the substrates 11 and 12 and defines a non-light emitting zone 21 with the frit glass 22. That is, the non-light emitting zone 21 is defined between the outermost partition 23 and the frit glass 22. Since the second electrode 13b is not formed in the non-light emitting zone 21, and since the fluorescent substance 18 is not coated thereon, theoretically, no discharge is generated. The non-light emitting zone 21 is also called a dummy and margin zone, and is formed at the outskirts of a display where an image is displayed. Within the dummy and margin zone 21, the dummy zone prevents an edge effect that may occur in discharge cells 19 at the outermost area of the display, and the margin zone compensates for a limit in accuracy of the manufacturing processes. The dummy and margin zone 21 is designed considering a property of each of the layers of a plasma display panel. However, since the non-light emission zone 21 is actually filled with the discharge gas filled in the discharge cell 19, when the sustaining discharge is generated between a pair of first electrodes 13a, discharge is generated in the non-light emitting zone 21. Such a mis-discharge phenomenon causes light emission by the discharge gas itself. In particular, a light emission phenomenon of an orange color occurs. Thus, the overall color purity of a display is lowered due to the presence of the non-light emitting zone 21.
To prevent such a phenomenon, a dummy electrode is used in the conventional technology. For example, a plurality of dummy electrodes is formed parallel to an address electrode at a portion corresponding to the outermost portion of a display area. The dummy electrodes are electrically connected to one another to be connected in common with an external connection terminal. Also, a dummy electrode is formed parallel to an address electrode at a portion corresponding to the outermost portion of a display area. The outermost address electrode and the dummy electrode are electrically connected to each other. Further, a plurality of dummy electrodes is formed parallel to an address electrode at a portion corresponding to the outermost portion of a display area. The outermost address electrode and the dummy electrode are electrically connected to each other. A predetermined voltage is applied to the outermost address electrode during a priming discharge period, an address discharge period, and a sustain discharge period. However, since the above conventional technologies require an additional dummy electrode, the structures thereof become complicated.